pomerium/docs/reference/readme.md

---
title: Settings
lang: en-US
sidebarDepth: 2
meta:
  - name: keywords
    content: configuration options settings pomerium
---

# Configuration Settings

Pomerium can be configured using a configuration file ([YAML]/[JSON]/[TOML]) or [environmental variables]. In general, environmental variable keys are identical to config file keys but are uppercase. If you are coming from a kubernetes or docker background this should feel familiar. If not, check out the following primers.

- [Store config in the environment](https://12factor.net/config)
- [Kubernetes: Environment variables](https://kubernetes.io/docs/tasks/inject-data-application/define-environment-variable-container/)
- [Kubernetes: Config Maps](https://kubernetes.io/docs/tasks/configure-pod-container/configure-pod-configmap/)
- [Docker: Environment variables](https://docs.docker.com/compose/environment-variables/)

Using both [environmental variables] and config file keys is allowed and encouraged (for instance, secret keys are probably best set as environmental variables). However, if duplicate configuration keys are found, environment variables take precedence.

:::tip

Pomerium can hot-reload route configuration details, authorization policy, certificates, and other proxy settings.

:::


## Shared Settings
These configuration variables are shared by all services, in all service modes.


### Address
- Environmental Variable: `ADDRESS`
- Config File Key: `address`
- Type: `string`
- Example: `:443`, `:8443`
- Default: `:443`
- Required

Address specifies the host and port to serve HTTP requests from. If empty, `:443` is used. Note, in all-in-one deployments, gRPC traffic will be served on loopback on port `:5443`.


### Autocert
- Environmental Variable: `AUTOCERT`
- Config File Key: `autocert`
- Type: `bool`
- Optional

Turning on autocert allows Pomerium to automatically retrieve, manage, and renew public facing TLS certificates from [Let's Encrypt][letsencrypt] which includes managed routes and the authenticate service.  [Autocert Directory](./#autocert-directory) must be used with Autocert must have a place to persist, and share certificate data between services. Note that autocert also provides [OCSP stapling](https://en.wikipedia.org/wiki/OCSP_stapling).

This setting can be useful in situations where you may not have Pomerium behind a TLS terminating ingress or proxy that is already handling your public certificates on your behalf.

:::warning

By using autocert, you agree to the [Let's Encrypt Subscriber Agreement](https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf). There are [_strict_ usage limits](https://letsencrypt.org/docs/rate-limits/) per domain you should be aware of. Consider testing with `autocert_use_staging` first.

:::

:::warning

Autocert requires that ports `80`/`443` be accessible from the internet in order to complete a [TLS-ALPN-01 challenge](https://letsencrypt.org/docs/challenge-types/#tls-alpn-01).

:::


### Autocert Must-Staple
- Environmental Variable: `AUTOCERT_MUST_STAPLE`
- Config File Key: `autocert_must_staple`
- Type: `bool`
- Optional

If true, force autocert to request a certificate with the `status_request` extension (commonly called `Must-Staple`). This allows the TLS client (_id est_ the browser) to fail immediately if the TLS handshake doesn't include OCSP stapling information. This setting is only used when [Autocert](./#autocert) is true.

:::tip

This setting will only take effect when you request or renew your certificates.

:::

For more details, please see [RFC7633](https://tools.ietf.org/html/rfc7633) .


### Autocert Directory
- Environmental Variable: either `AUTOCERT_DIR`
- Config File Key: `autocert_dir`
- Type: `string` pointing to the path of the directory
- Required if using [Autocert](./#autocert) setting
- Default:

  - `/data/autocert` in published Pomerium docker images
  - [$XDG_DATA_HOME](https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html)
  - `$HOME/.local/share/pomerium`

Autocert directory is the path which autocert will store x509 certificate data.


### Autocert Use Staging
- Environmental Variable: `AUTOCERT_USE_STAGING`
- Config File Key: `autocert_use_staging`
- Type: `bool`
- Optional

Let's Encrypt has strict [usage limits](https://letsencrypt.org/docs/rate-limits/). Enabling this setting allows you to use Let's Encrypt's [staging environment](https://letsencrypt.org/docs/staging-environment/) which has much more lax usage limits.


### Certificates
- Config File Key: `certificates` (not yet settable using environmental variables)
- Config File Key: `certificate` / `certificate_key`
- Config File Key: `certificate_file` / `certificate_key_file`
- Environmental Variable: `CERTIFICATE` / `CERTIFICATE_KEY`
- Environmental Variable: `CERTIFICATE_FILE` / `CERTIFICATE_KEY_FILE`
- Type: array of relative file locations `string`
- Type: [base64 encoded] `string`
- Type: certificate relative file location `string`
- Required (if insecure not set)

Certificates are the x509 _public-key_ and _private-key_ used to establish secure HTTP and gRPC connections. Any combination of the above can be used together, and are additive. You can also use any of these settings in conjunction with `Autocert` to get OCSP stapling.

For example, if specifying multiple certificates at once:

```yaml
certificates:
  - cert: "$HOME/.acme.sh/authenticate.example.com_ecc/fullchain.cer"
    key: "$HOME/.acme.sh/authenticate.example.com_ecc/authenticate.example.com.key"
  - cert: "$HOME/.acme.sh/verify.example.com_ecc/fullchain.cer"
    key: "$HOME/.acme.sh/verify.example.com_ecc/verify.example.com.key"
  - cert: "$HOME/.acme.sh/prometheus.example.com_ecc/fullchain.cer"
    key: "$HOME/.acme.sh/prometheus.example.com_ecc/prometheus.example.com.key"
```


### Client Certificate Authority
- Environment Variable: `CLIENT_CA` / `CLIENT_CA_FILE`
- Config File Key: `client_ca` / `client_ca_file`
- Type: [base64 encoded] `string` or relative file location
- Optional

The Client Certificate Authority is the x509 _public-key_ used to validate [mTLS](https://en.wikipedia.org/wiki/Mutual_authentication) client certificates. If not set, no client certificate will be required.


### Cookie Options

#### Cookie Name
- Environmental Variable: `COOKIE_NAME`
- Config File Key: `cookie_name`
- Type: `string`
- Default: `_pomerium`

The name of the session cookie sent to clients.


#### Cookie Secret
- Environmental Variable: `COOKIE_SECRET`
- Config File Key: `cookie_secret`
- Type: [base64 encoded] `string`
- Required for proxy service

Secret used to encrypt and sign session cookies. You can generate a random key with `head -c32 /dev/urandom | base64`.


#### Cookie Domain
- Environmental Variable: `COOKIE_DOMAIN`
- Config File Key: `cookie_domain`
- Type: `string`
- Example: `localhost.pomerium.io`
- Optional

The scope of session cookies issued by Pomerium.


#### HTTPS only
- Environmental Variable: `COOKIE_SECURE`
- Config File Key: `cookie_secure`
- Type: `bool`
- Default: `true`

If true, instructs browsers to only send user session cookies over HTTPS.

:::warning

Setting this to false may result in session cookies being sent in cleartext.

:::


#### Javascript Security
- Environmental Variable: `COOKIE_HTTP_ONLY`
- Config File Key: `cookie_http_only`
- Type: `bool`
- Default: `true`

If true, prevents javascript in browsers from reading user session cookies.

:::warning

Setting this to false enables hostile javascript to steal session cookies and impersonate users.

:::


#### Expiration
- Environmental Variable: `COOKIE_EXPIRE`
- Config File Key: `cookie_expire`
- Type: [Go Duration](https://golang.org/pkg/time/#Duration.String) `string`
- Default: `14h`

Sets the lifetime of session cookies. After this interval, users must reauthenticate.


### Debug
- Environmental Variable: `POMERIUM_DEBUG`
- Config File Key: `pomerium_debug`
- Type: `bool`
- Default: `false`

::: danger

Enabling the debug flag could result in sensitive information being logged!!!

:::

By default, JSON encoded logs are produced. Debug enables colored, human-readable logs to be streamed to [standard out](https://en.wikipedia.org/wiki/Standard_streams#Standard_output_(stdout)>>>). In production, it is recommended to be set to `false`.

For example, if `true`

```
10:37AM INF cmd/pomerium version=v0.0.1-dirty+ede4124
10:37AM INF proxy: new route from=verify.localhost.pomerium.io to=https://verify.pomerium.com
10:37AM INF proxy: new route from=ssl.localhost.pomerium.io to=http://neverssl.com
10:37AM INF proxy/authenticator: grpc connection OverrideCertificateName= addr=auth.localhost.pomerium.io:443
```

If `false`

```
{"level":"info","version":"v0.0.1-dirty+ede4124","time":"2019-02-18T10:41:03-08:00","message":"cmd/pomerium"}
{"level":"info","from":"verify.localhost.pomerium.io","to":"https://verify.pomerium.com","time":"2019-02-18T10:41:03-08:00","message":"proxy: new route"}
{"level":"info","from":"ssl.localhost.pomerium.io","to":"http://neverssl.com","time":"2019-02-18T10:41:03-08:00","message":"proxy: new route"}
{"level":"info","OverrideCertificateName":"","addr":"auth.localhost.pomerium.io:443","time":"2019-02-18T10:41:03-08:00","message":"proxy/authenticator: grpc connection"}
```


### Forward Auth
- Environmental Variable: `FORWARD_AUTH_URL`
- Config File Key: `forward_auth_url`
- Type: `URL` (must contain a scheme and hostname)
- Example: `https://forwardauth.corp.example.com`
- Resulting Verification URL: `https://forwardauth.corp.example.com/?uri={URL-TO-VERIFY}`
- Optional

Forward authentication creates an endpoint that can be used with third-party proxies that do not have rich access control capabilities ([nginx](http://nginx.org/en/docs/http/ngx_http_auth_request_module.html), [nginx-ingress](https://kubernetes.github.io/ingress-nginx/examples/auth/oauth-external-auth/), [ambassador](https://www.getambassador.io/reference/services/auth-service/), [traefik](https://docs.traefik.io/middlewares/forwardauth/)). Forward authentication allows you to delegate authentication and authorization for each request to Pomerium.

#### Request flow

![pomerium forward auth request flow](./img/auth-flow-diagram.svg)

#### Examples

##### NGINX Ingress

Some reverse-proxies, such as nginx split access control flow into two parts: verification and sign-in redirection. Notice the additional path `/verify` used for `auth-url` indicating to Pomerium that it should return a `401` instead of redirecting and starting the sign-in process.

```yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: verify
  annotations:
    kubernetes.io/ingress.class: "nginx"
    certmanager.k8s.io/issuer: "letsencrypt-prod"
    nginx.ingress.kubernetes.io/auth-url: https://forwardauth.corp.example.com/verify?uri=$scheme://$host$request_uri
    nginx.ingress.kubernetes.io/auth-signin: "https://forwardauth.corp.example.com/?uri=$scheme://$host$request_uri"
spec:
  tls:
    - hosts:
        - verify.corp.example.com
      secretName: quickstart-example-tls
  rules:
    - host: verify.corp.example.com
      http:
        paths:
          - path: /
            backend:
              serviceName: verify
              servicePort: 80
```

#### Traefik docker-compose

If the `forward_auth_url` is also handled by Traefik, you will need to configure Traefik to trust the `X-Forwarded-*` headers as described in [the documentation](https://docs.traefik.io/v2.2/routing/entrypoints/#forwarded-headers).

```yml
version: "3"

services:
  traefik:
    # The official v2.2 Traefik docker image
    image: traefik:v2.2
    # Enables the web UI and tells Traefik to listen to docker
    command:
      - "--api.insecure=true"
      - "--providers.docker=true"
      - "--entrypoints.web.address=:80"
      - "--entrypoints.web.forwardedheaders.insecure=true"
    ports:
      # The HTTP port
      - "80:80"
      # The Web UI (enabled by --api.insecure=true)
      - "8080:8080"
    volumes:
      # So that Traefik can listen to the Docker events
      - /var/run/docker.sock:/var/run/docker.sock
  verify:
    # A container that exposes an API to show its IP address
    image: pomerium/verify:latest
    labels:
      - "traefik.http.routers.verify.rule=Host(`verify.corp.example.com`)"
      # Create a middleware named `foo-add-prefix`
      - "traefik.http.middlewares.test-auth.forwardauth.authResponseHeaders=X-Pomerium-Authenticated-User-Email,x-pomerium-authenticated-user-id,x-pomerium-authenticated-user-groups,x-pomerium-jwt-assertion"
      - "traefik.http.middlewares.test-auth.forwardauth.address=http://forwardauth.corp.example.com/?uri=https://verify.corp.example.com"
      - "traefik.http.routers.verify.middlewares=test-auth@docker"
```


### Global Timeouts
- Environmental Variables: `TIMEOUT_READ` `TIMEOUT_WRITE` `TIMEOUT_IDLE`
- Config File Key: `timeout_read` `timeout_write` `timeout_idle`
- Type: [Go Duration](https://golang.org/pkg/time/#Duration.String) `string`
- Example: `TIMEOUT_READ=30s`
- Defaults: `TIMEOUT_READ=30s` `TIMEOUT_WRITE=0` `TIMEOUT_IDLE=5m`

Timeouts set the global server timeouts. Timeouts can also be set for individual [routes](./#policy).

![cloudflare blog on timeouts](https://blog.cloudflare.com/content/images/2016/06/Timeouts-001.png)

> For a deep dive on timeout values see [these](https://blog.cloudflare.com/the-complete-guide-to-golang-net-http-timeouts/) [two](https://blog.cloudflare.com/exposing-go-on-the-internet/) excellent blog posts.


### GRPC Options

#### GRPC Address
- Environmental Variable: `GRPC_ADDRESS`
- Config File Key: `grpc_address`
- Type: `string`
- Example: `:443`, `:8443`
- Default: `:443` or `:5443` if in all-in-one mode

gRPC Address specifies the host and port to serve gRPC requests from.


#### GRPC Insecure
- Environmental Variable: `GRPC_INSECURE`
- Config File Key: `grpc_insecure`
- Type: `bool`

This setting disables transport security for gRPC communication. If running in all-in-one mode, defaults to true as communication will run over localhost's own socket.


#### GRPC Client Timeout
- Environmental Variable: `GRPC_CLIENT_TIMEOUT`
- Config File Key: `grpc_client_timeout`
- Type: [Go Duration](https://golang.org/pkg/time/#Duration.String) `string`
- Default: `10s`

Maximum time before canceling an upstream gRPC request. During transient failures, the proxy will retry upstreams for this duration. You should leave this high enough to handle backend service restart and rediscovery so that client requests do not fail.


#### GRPC Client DNS RoundRobin
- Environmental Variable: `GRPC_CLIENT_DNS_ROUNDROBIN`
- Config File Key: `grpc_client_dns_roundrobin`
- Type: `bool`
- Default: `true`

Enable gRPC DNS based round robin load balancing. This method uses DNS to resolve endpoints and does client side load balancing of _all_ addresses returned by the DNS record. Do not disable unless you have a specific use case.


#### GRPC Server Max Connection Age
- Environmental Variable: `GRPC_SERVER_MAX_CONNECTION_AGE`
- Config File Key: `grpc_server_max_connection_age`
- Type: [Go Duration](https://golang.org/pkg/time/#Duration.String) `string`
- Default: `5m`

Set max connection age for GRPC servers. After this interval, servers ask clients to reconnect and perform any rediscovery for new/updated endpoints from DNS.

See <https://godoc.org/google.golang.org/grpc/keepalive#ServerParameters> for details


#### GRPC Server Max Connection Age Grace
- Environmental Variable: `GRPC_SERVER_MAX_CONNECTION_AGE_GRACE`
- Config File Key: `grpc_server_max_connection_age_grace`
- Type: [Go Duration](https://golang.org/pkg/time/#Duration.String) `string`
- Default: `5m`

Additive period with `grpc_server_max_connection_age`, after which servers will force connections to close.

See <https://godoc.org/google.golang.org/grpc/keepalive#ServerParameters> for details


### HTTP Redirect Address
- Environmental Variable: `HTTP_REDIRECT_ADDR`
- Config File Key: `http_redirect_addr`
- Type: `string`
- Example: `:80`, `:8080`
- Optional

If set, the HTTP Redirect Address specifies the host and port to redirect http to https traffic on. If unset, no redirect server is started.


### Insecure Server
- Environmental Variable: `INSECURE_SERVER`
- Config File Key: `insecure_server`
- Type: `bool`
- Required if certificates unset

Turning on insecure server mode will result in pomerium starting, and operating without any protocol encryption in transit.

This setting can be useful in a situation where you have Pomerium behind a TLS terminating ingress or proxy. However, even in that case, it is highly recommended to use TLS to protect the confidentiality and integrity of service communication even behind the ingress using self-signed certificates or an internal CA. Please see our helm-chart for an example of just that.

:::warning

Pomerium should _never_ be exposed to the internet without TLS encryption.

:::


### DNS Lookup Family
- Environmental Variable: `DNS_LOOKUP_FAMILY`
- Config File Key: `dns_lookup_family`
- Type: `string`
- Options: `V4_ONLY` `V6_ONLY` `AUTO`
- Optional

The DNS IP address resolution policy. If not specified, the value defaults to `AUTO`.


### Log Level
- Environmental Variable: `LOG_LEVEL`
- Config File Key: `log_level`
- Type: `string`
- Options: `debug` `info` `warn` `error`
- Default: `debug`

Log level sets the global logging level for pomerium. Only logs of the desired level and above will be logged.


### Metrics Address
- Environmental Variable: `METRICS_ADDRESS`
- Config File Key: `metrics_address`
- Type: `string`
- Example: `:9090`, `127.0.0.1:9090`
- Default: `disabled`
- Optional

Expose a prometheus endpoint on the specified port.

:::warning

**Use with caution:** the endpoint can expose frontend and backend server names or addresses. Do not externally expose the metrics if this is sensitive information.

:::

#### Pomerium Metrics Tracked

Name                                          | Type      | Description
--------------------------------------------- | --------- | -----------------------------------------------------------------------
grpc_client_request_duration_ms               | Histogram | GRPC client request duration by service
grpc_client_request_size_bytes                | Histogram | GRPC client request size by service
grpc_client_requests_total                    | Counter   | Total GRPC client requests made by service
grpc_client_response_size_bytes               | Histogram | GRPC client response size by service
grpc_server_request_duration_ms               | Histogram | GRPC server request duration by service
grpc_server_request_size_bytes                | Histogram | GRPC server request size by service
grpc_server_requests_total                    | Counter   | Total GRPC server requests made by service
grpc_server_response_size_bytes               | Histogram | GRPC server response size by service
http_client_request_duration_ms               | Histogram | HTTP client request duration by service
http_client_request_size_bytes                | Histogram | HTTP client request size by service
http_client_requests_total                    | Counter   | Total HTTP client requests made by service
http_client_response_size_bytes               | Histogram | HTTP client response size by service
http_server_request_duration_ms               | Histogram | HTTP server request duration by service
http_server_request_size_bytes                | Histogram | HTTP server request size by service
http_server_requests_total                    | Counter   | Total HTTP server requests handled by service
http_server_response_size_bytes               | Histogram | HTTP server response size by service
pomerium_build_info                           | Gauge     | Pomerium build metadata by git revision, service, version and goversion
pomerium_config_checksum_int64                | Gauge     | Currently loaded configuration checksum by service
pomerium_config_last_reload_success           | Gauge     | Whether the last configuration reload succeeded by service
pomerium_config_last_reload_success_timestamp | Gauge     | The timestamp of the last successful configuration reload by service
redis_conns                                   | Gauge     | Number of total connections in the pool
redis_idle_conns                              | Gauge     | Total number of times free connection was found in the pool
redis_wait_count_total                        | Counter   | Total number of connections waited for
redis_wait_duration_ms_total                  | Counter   | Total time spent waiting for connections
storage_operation_duration_ms                 | Histogram | Storage operation duration by operation, result, backend and service

#### Envoy Proxy Metrics

As of `v0.9`, Pomerium uses [envoy](https://www.envoyproxy.io/) for the data plane. As such, proxy related metrics are sourced from envoy, and use envoy's internal [stats data model](https://www.envoyproxy.io/docs/envoy/latest/operations/stats_overview). Please see Envoy's documentation for information about specific metrics.

All metrics coming from envoy will be labeled with `service="pomerium"` or `service="pomerium-proxy"`, depending if you're running all-in-one or distributed service mode.


### Metrics Basic Authentication
- Environmental Variable: `METRICS_BASIC_AUTH`
- Config File Key: `metrics_basic_auth`
- Type: base64 encoded `string` of `username:password`
- Example: `eDp5` (for username: x, and password: y)
- Default: ``
- Optional

Require [Basic HTTP Authentication](https://tools.ietf.org/html/rfc7617) to access the metrics endpoint.

To support this in Prometheus, consult the `basic_auth` option in the [`scrape_config`](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config)
documentation.


### Metrics Certificate
- Config File Key: `metrics_certificate` / `metrics_certificate_key`
- Config File Key: `metrics_certificate_file` / `metrics_certificate_key_file`
- Environmental Variable: `METRICS_CERTIFICATE` / `METRICS_CERTIFICATE_KEY`
- Environmental Variable: `METRICS_CERTIFICATE_FILE` / `METRICS_CERTIFICATE_KEY_FILE`
- Type: [base64 encoded] `string`
- Type: certificate relative file location `string`
- Optional

Certificates are the x509 _public-key_ and _private-key_ used to secure the metrics endpoint.


### Metrics Client Certificate Authority
- Environment Variable: `METRICS_CLIENT_CA` / `METRICS_CLIENT_CA_FILE`
- Config File Key: `metrics_client_ca` / `metrics_client_ca_file`
- Type: [base64 encoded] `string` or relative file location
- Optional

The Client Certificate Authority is the x509 _public-key_ used to validate [mTLS](https://en.wikipedia.org/wiki/Mutual_authentication) client certificates for the metrics endpoint. If not set, no client certificate will be required.


### Proxy Log Level
- Environmental Variable: `PROXY_LOG_LEVEL`
- Config File Key: `proxy_log_level`
- Type: `string`
- Options: `debug` `info` `warn` `error`
- Default: value of `log_level` or `debug` if both are unset

Proxy log level sets the logging level for the pomerium proxy service access logs. Only logs of the desired level and above will be logged.


### Service Mode
- Environmental Variable: `SERVICES`
- Config File Key: `services`
- Type: `string`
- Default: `all`
- Options: `all` `authenticate` `authorize` `databroker` or `proxy`

Service mode sets which service(s) to run. If testing, you may want to set to `all` and run pomerium in "all-in-one mode." In production, you'll likely want to spin up several instances of each service mode for high availability.


### Shared Secret
- Environmental Variable: `SHARED_SECRET`
- Config File Key: `shared_secret`
- Type: [base64 encoded] `string`
- Required

Shared Secret is the base64 encoded 256-bit key used to mutually authenticate requests between services. It's critical that secret keys are random, and stored safely. Use a key management system or `/dev/urandom` to generate a key. For example:

```
head -c32 /dev/urandom | base64
```


### Tracing
Tracing tracks the progression of a single user request as it is handled by Pomerium.

Each unit work is called a Span in a trace. Spans include metadata about the work, including the time spent in the step (latency), status, time events, attributes, links. You can use tracing to debug errors and latency issues in your applications, including in downstream connections.

#### Shared Tracing Settings

Config Key          | Description                                                                          | Required
:------------------ | :----------------------------------------------------------------------------------- | --------
tracing_provider    | The name of the tracing provider. (e.g. jaeger, zipkin)                              | ✅
tracing_sample_rate | Percentage of requests to sample in decimal notation. Default is `0.0001`, or `.01%` | ❌

#### Datadog

Datadog is a real-time monitoring system that supports distributed tracing and monitoring.

Config Key              | Description                                                                  | Required
:---------------------- | :--------------------------------------------------------------------------- | --------
tracing_datadog_address | `host:port` address of the Datadog Trace Agent. Defaults to `localhost:8126` | ❌

#### Jaeger (partial)

**Warning** At this time, Jaeger protocol does not capture spans inside the proxy service. Please use Zipkin protocol with Jaeger for full support.

[Jaeger](https://www.jaegertracing.io/) is a distributed tracing system released as open source by Uber Technologies. It is used for monitoring and troubleshooting microservices-based distributed systems, including:

- Distributed context propagation
- Distributed transaction monitoring
- Root cause analysis
- Service dependency analysis
- Performance / latency optimization

Config Key                        | Description                                 | Required
:-------------------------------- | :------------------------------------------ | --------
tracing_jaeger_collector_endpoint | Url to the Jaeger HTTP Thrift collector.    | ✅
tracing_jaeger_agent_endpoint     | Send spans to jaeger-agent at this address. | ✅

#### Zipkin

Zipkin is an open source distributed tracing system and protocol.

Many tracing backends support zipkin either directly or through intermediary agents, including Jaeger. For full tracing support, we recommend using the Zipkin tracing protocol.

Config Key              | Description                      | Required
:---------------------- | :------------------------------- | --------
tracing_zipkin_endpoint | Url to the Zipkin HTTP endpoint. | ✅

#### Example

![jaeger example trace](./img/jaeger.png)


### Use Proxy Protocol
- Environment Variable: `USE_PROXY_PROTOCOL`
- Config File Key: `use_proxy_protocol`
- Type: `bool`
- Optional

Setting `use_proxy_protocol` will configure Pomerium to require the [HAProxy proxy protocol](https://www.haproxy.org/download/1.9/doc/proxy-protocol.txt) on incoming connections. Versions 1 and 2 of the protocol are supported.


### Envoy Admin Options
- Environment Variable: `ENVOY_ADMIN_ADDRESS`, `ENVOY_ADMIN_ACCESS_LOG_PATH`, `ENVOY_ADMIN_PROFILE_PATH`
- Config File Keys: `envoy_admin_address`, `envoy_admin_access_log_path`, `envoy_admin_profile_path`
- Type: `string`
- Optional

These options customize Envoy's [bootstrap configuration](https://www.envoyproxy.io/docs/envoy/latest/operations/admin#operations-admin-interface). They cannot be modified at runtime.


## Authenticate Service

### Authenticate Callback Path
- Environmental Variable: `AUTHENTICATE_CALLBACK_PATH`
- Config File Key: `authenticate_callback_path`
- Type: `string`
- Default: `/oauth2/callback`
- Optional

Authenticate callback path sets the path at which the authenticate service receives callback responses from your identity provider. The value must exactly match one of the authorized redirect URIs for the OAuth 2.0 client.

This value is referred to as the `redirect_url` in the [OpenIDConnect][oidc rfc] and OAuth2 specs.

See also:

- [OAuth2 RFC 6749](https://tools.ietf.org/html/rfc6749#section-3.1.2)
- [OIDC Spec][oidc rfc]
- [Google - Setting Redirect URI](https://developers.google.com/identity/protocols/OpenIDConnect#setredirecturi)


### Authenticate Service URL
- Environmental Variable: `AUTHENTICATE_SERVICE_URL`
- Config File Key: `authenticate_service_url`
- Type: `URL`
- Required
- Example: `https://authenticate.corp.example.com`

Authenticate Service URL is the externally accessible URL for the authenticate service.


### Identity Provider Client ID
- Environmental Variable: `IDP_CLIENT_ID`
- Config File Key: `idp_client_id`
- Type: `string`
- Required

Client ID is the OAuth 2.0 Client Identifier retrieved from your identity provider. See your identity provider's documentation, and our [identity provider] docs for details.


### Identity Provider Client Secret
- Environmental Variable: `IDP_CLIENT_SECRET`
- Config File Key: `idp_client_secret`
- Type: `string`
- Required

Client Secret is the OAuth 2.0 Secret Identifier retrieved from your identity provider. See your identity provider's documentation, and our [identity provider] docs for details.


### Identity Provider Name
- Environmental Variable: `IDP_PROVIDER`
- Config File Key: `idp_provider`
- Type: `string`
- Required
- Options: `auth0` `azure` `google` `okta` `onelogin` or `oidc`

Provider is the short-hand name of a built-in OpenID Connect (oidc) identity provider to be used for authentication. To use a generic provider,set to `oidc`.

See [identity provider] for details.


### Identity Provider Scopes
- Environmental Variable: `IDP_SCOPES`
- Config File Key: `idp_scopes`
- Type: list of `string`
- Default: `oidc`,`profile`, `email`, `offline_access` (typically)
- Optional for built-in identity providers.

Identity provider scopes correspond to access privilege scopes as defined in Section 3.3 of OAuth 2.0 RFC6749\. The scopes associated with Access Tokens determine what resources will be available when they are used to access OAuth 2.0 protected endpoints.

:::warning

If you are using a built-in provider, you probably don't want to set customized scopes.

:::

:::warning

Some providers, like Amazon Cognito, _do not_ support the `offline_access` scope.

:::


### Identity Provider Service Account
- Environmental Variable: `IDP_SERVICE_ACCOUNT`
- Config File Key: `idp_service_account`
- Type: `string`
- **Required** for group based policies (most configurations)

The identity provider service account setting is used to query associated identity information from your identity provider.

:::warning

If you plan to write authorization policies using groups, or any other data that exists in your identity provider's directory service, this setting is **mandatory**.

:::


### Identity Provider URL
- Environmental Variable: `IDP_PROVIDER_URL`
- Config File Key: `idp_provider_url`
- Type: `string`
- Required, depending on provider

Provider URL is the base path to an identity provider's [OpenID connect discovery document](https://openid.net/specs/openid-connect-discovery-1_0.html). For example, google's URL would be `https://accounts.google.com` for [their discover document](https://accounts.google.com/.well-known/openid-configuration).


### Identity Provider Request Params
- Environmental Variable: `IDP_REQUEST_PARAMS`
- Config File Key: `idp_request_params`
- Type: map of `strings` key value pairs
- Optional

Request parameters to be added as part of a signin request using OAuth2 code flow.

For more information see:

- [OIDC Request Parameters](https://openid.net/specs/openid-connect-basic-1_0.html#RequestParameters)
- [IANA OAuth Parameters](https://www.iana.org/assignments/oauth-parameters/oauth-parameters.xhtml)
- [Microsoft Azure Request params](https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-auth-code-flow#request-an-authorization-code)
- [Google Authentication URI parameters](https://developers.google.com/identity/protocols/oauth2/openid-connect)


### Identity Provider Refresh Directory Settings
- Environmental Variables: `IDP_REFRESH_DIRECTORY_INTERVAL` `IDP_REFRESH_DIRECTORY_TIMEOUT`
- Config File Key: `idp_refresh_directory_interval` `idp_refresh_directory_timeout`
- Type: [Go Duration](https://golang.org/pkg/time/#Duration.String) `string`
- Example: `IDP_REFRESH_DIRECTORY_INTERVAL=30m`
- Defaults: `IDP_REFRESH_DIRECTORY_INTERVAL=10m` `IDP_REFRESH_DIRECTORY_TIMEOUT=1m`

Refresh directory interval is the time that pomerium will sync your IDP diretory, while refresh directory timeout is the maximum time allowed each run.

:::warning

Use it at your own risk, if you set a too low value, you may reach IDP API rate limit.

:::


## Proxy Service

### Authenticate Service URL
- Environmental Variable: `AUTHENTICATE_SERVICE_URL`
- Config File Key: `authenticate_service_url`
- Type: `URL`
- Required
- Example: `https://authenticate.corp.example.com`

Authenticate Service URL is the externally accessible URL for the authenticate service.


### Authorize Service URL
- Environmental Variable: `AUTHORIZE_SERVICE_URL`
- Config File Key: `authorize_service_url`
- Type: `URL`
- Required; inferred in all-in-one mode to be localhost.
- Example: `https://pomerium-authorize-service.default.svc.cluster.local` or `https://localhost:5443`

Authorize Service URL is the location of the internally accessible authorize service. NOTE: Unlike authenticate, authorize has no publicly accessible http handlers so this setting is purely for gRPC communication.

If your load balancer does not support gRPC pass-through you'll need to set this value to an internally routable location (`https://pomerium-authorize-service.default.svc.cluster.local`) instead of an externally routable one (`https://authorize.corp.example.com`).


### Certificate Authority
- Environmental Variable: `CERTIFICATE_AUTHORITY` or `CERTIFICATE_AUTHORITY_FILE`
- Config File Key: `certificate_authority` or `certificate_authority_file`
- Type: [base64 encoded] `string` or relative file location
- Optional

Certificate Authority is set when behind-the-ingress service communication uses custom or self-signed certificates.

:::warning

Be sure to include the intermediary certificate.

:::


### Default Upstream Timeout
- Environmental Variable: `DEFAULT_UPSTREAM_TIMEOUT`
- Config File Key: `default_upstream_timeout`
- Type: [Duration](https://golang.org/pkg/time/#Duration) `string`
- Example: `10m`, `1h45m`
- Default: `30s`

Default Upstream Timeout is the default timeout applied to a proxied route when no `timeout` key is specified by the policy.


### Set Response Headers
- Environmental Variable: `SET_RESPONSE_HEADERS`
- Config File Key: `set_response_headers`
- Type: map of `strings` key value pairs
- Examples:

  - Comma Separated: `X-Content-Type-Options:nosniff,X-Frame-Options:SAMEORIGIN`
  - JSON: `'{"X-Test": "X-Value"}'`
  - YAML:

    ```yaml
    set_response_headers:
      X-Test: X-Value
    ```

- To disable: `disable:true`

- Default :

  ```javascript
  X-Content-Type-Options : nosniff,
  X-Frame-Options:SAMEORIGIN,
  X-XSS-Protection:1; mode=block,
  Strict-Transport-Security:max-age=31536000; includeSubDomains; preload,
  ```

Set Response Headers specifies a mapping of [HTTP Header](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers) to be added globally to all managed routes and pomerium's authenticate service.

By default, conservative [secure HTTP headers](https://www.owasp.org/index.php/OWASP_Secure_Headers_Project) are set.

![pomerium security headers](./img/security-headers.png)


### JWT Claim Headers
- Environmental Variable: `JWT_CLAIMS_HEADERS`
- Config File Key: `jwt_claims_headers`
- Type: slice of `string`
- Example: `email`,`groups`, `user`
- Optional

The JWT Claim Headers setting allows you to pass specific user session data down to upstream applications as HTTP request headers. Note, unlike the header `x-pomerium-jwt-assertion` these values are not signed by the authorization service.

Any claim in the pomerium session JWT can be placed into a corresponding header for upstream consumption. This claim information is sourced from your Identity Provider (IdP) and Pomerium's own session metadata. The header will have the following format:

`X-Pomerium-Claim-{Name}` where `{Name}` is the name of the claim requested.

This option also supports a nested object to customize the header name. For example:

```yaml
jwt_claims_headers:
  X-Email: email
```

Will add an `X-Email` header with a value of the `email` claim.

Use this option if you previously relied on `x-pomerium-authenticated-user-{email|user-id|groups}`.


### Override Certificate Name
- Environmental Variable: `OVERRIDE_CERTIFICATE_NAME`
- Config File Key: `override_certificate_name`
- Type: `int`
- Optional
- Example: `*.corp.example.com` if wild card or `authenticate.corp.example.com`/`authorize.corp.example.com`

Secure service communication can fail if the external certificate does not match the internally routed service hostname/[SNI](https://en.wikipedia.org/wiki/Server_Name_Indication). This setting allows you to override that value.


### Programmatic Redirect Domain Whitelist
- Config File Key: `programmatic_redirect_domain_whitelist`
- Type: array of `string`
- Optional
- Default: `localhost`

The programmatic redirect domain whitelist is used to restrict the allowed redirect URLs when using programmatic login. By default only `localhost` URLs are allowed.


### Refresh Cooldown
- Environmental Variable: `REFRESH_COOLDOWN`
- Config File Key: `refresh_cooldown`
- Type: [Duration](https://golang.org/pkg/time/#Duration) `string`
- Example: `10m`, `1h45m`
- Default: `5m`

Refresh cooldown is the minimum amount of time between allowed manually refreshed sessions.


### X-Forwarded-For HTTP Header
- Environmental Variable: `SKIP_XFF_APPEND`
- Config File Key: `skip_xff_append`
- Type: `bool`
- Default: `false`

Do not append proxy IP address to `x-forwarded-for` HTTP header. See [Envoy](https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_conn_man/headers.html?highlight=skip_xff_append#x-forwarded-for) docs for more detail.


### The number of trusted hops
- Environmental Variable: `XFF_NUM_TRUSTED_HOPS`
- Config File Key: `xff_num_trusted_hops`
- Type: `uint32`
- Default: `0`

The number of trusted reverse proxies in front of pomerium. This affects `x-forwarded-proto` header and [`x-envoy-external-address` header](https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_conn_man/headers#x-envoy-external-address), which reports tursted client address. [Envoy](https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_conn_man/headers.html?highlight=xff_num_trusted_hops#x-forwarded-for) docs for more detail.


### Codec Type
- Environment Variable: `CODEC_TYPE`
- Config File Key: `codec_type`
- Type: `string`
- Default: `auto` (`http1` in all-in-one mode)

Specifies the codec to use for downstream connections. Either `auto`, `http1` or `http2`.

When `auto` is specified the codec will be determined via TLS ALPN or protocol inference.

:::warning

With HTTP/2, browsers typically coalesce connections for the same IP address that use the same
TLS certificate. For example, you may have `authenticate.localhost.pomerium.io` and
`example.localhost.pomerium.io` using the same wildcard certificate (`*.localhost.pomerium.io`)
and both pointing to `127.0.0.1`. Your browser sees this and re-uses the initial connection
it makes to `example` for `authenticate`. But unfortunately the routes necessary to handle
`authenticate` don't exist on `example` so the proxy cannot handle the request.

If this happens Pomerium will respond with a `421 Misdirected Request` status. Most browsers will attempt to
make the request on a new HTTP/2 connection. However not all browsers implement this behavior
(notably Safari), and users may end up seeing a blank page instead.

If you see this happen, there are several ways to mitigate the problem:

1. Don't re-use TLS certificates for shared IP domains.
2. Don't re-use IP addresses for shared TLS certificates.
3. Don't use HTTP/2.

More details on this problem are available in [Github Issue #2150](https://github.com/pomerium/pomerium/issues/2150).

:::


## Data Broker Service
The databroker service is used for storing user session data.


### Data Broker Service URL
- Environmental Variable: `DATABROKER_SERVICE_URL` or `DATABROKER_SERVICE_URLS`
- Config File Key: `databroker_service_url` or `databroker_service_urls`
- Type: `URL`
- Example: `https://databroker.corp.example.com`
- Default: in all-in-one mode, `http://localhost:5443`

The data broker service URL points to a data broker which is responsible for storing associated authorization context (e.g. sessions, users and user groups). Multiple URLs can be specified with `databroker_service_url`.

By default, the `databroker` service uses an in-memory databroker.

To create your own data broker, implement the following gRPC interface:

- [pkg/grpc/databroker/databroker.proto](https://github.com/pomerium/pomerium/blob/master/pkg/grpc/databroker/databroker.proto)

For an example implementation, the in-memory database used by the databroker service can be found here:

- [pkg/databroker/memory](https://github.com/pomerium/pomerium/tree/master/pkg/databroker/memory)


### Data Broker Storage Type
- Environmental Variable: `DATABROKER_STORAGE_TYPE`
- Config File Key: `databroker_storage_type`
- Type: `string`
- Optional
- Example: `redis`,`memory`
- Default: `memory`

The backend storage that databroker server will use.


### Data Broker Storage Connection String
- Environmental Variable: `DATABROKER_STORAGE_CONNECTION_STRING`
- Config File Key: `databroker_storage_connection_string`
- Type: `string`
- **Required** when storage type is `redis`
- Example: `"redis://localhost:6379/0"`, `"rediss://localhost:6379/0"`

The connection string that the databroker service will use to connect to storage backend.

For `redis`, the following URL types are supported:

- simple: `redis://[username:password@]host:port/[db]`
- sentinel: `redis+sentinel://[:password@]host:port[,host2:port2,...]/[master_name[/db]][?param1=value1[&param2=value2&...]]`
- cluster: `redis+cluster://[username:password@]host:port[,host2:port2,...]/[?param1=value1[&param2=value=2&...]]`

You can also enable TLS with `rediss://`, `rediss+sentinel://` and `rediss+cluster://`.


### Data Broker Storage Certificate File
- Environment Variable: `DATABROKER_STORAGE_CERT_FILE`
- Config File Key: `databroker_storage_cert_file`
- Type: relative file location
- Optional

The certificate used to connect to a storage backend.


### Data Broker Storage Certificate Key File
- Environment Variable: `DATABROKER_STORAGE_KEY_FILE`
- Config File Key: `databroker_storage_key_file`
- Type: relative file location
- Optional

The certificate key used to connect to a storage backend.


### Data Broker Storage Certificate Authority
- Environment Variable: `DATABROKER_STORAGE_CA_FILE`
- Config File Key: `databroker_storage_ca_file`
- Type: relative file location
- Optional

This setting defines the set of root certificates used when verifying storage server connections.


### Data Broker Storage TLS Skip Verify
- Environment Variable: `DATABROKER_STORAGE_TLS_SKIP_VERIFY`
- Config File Key: `databroker_storage_tls_skip_verify`
- Type: relative file location
- Optional

If set, the TLS connection to the storage backend will not be verified.


## Policy
- Environmental Variable: `POLICY`
- Config File Key: `policy`
- Type: [base64 encoded] `string` or inline policy structure in config file
- **Required** However, pomerium will safely start without a policy configured, but will be unable to authorize or proxy traffic until the configuration is updated to contain a policy.

Policy contains route specific settings, and access control details. If you are configuring via POLICY environment variable, just the contents of the policy needs to be passed. If you are configuring via file, the policy should be present under the policy key. For example,

<<< @/examples/config/policy.example.yaml

Policy routes are checked in the order they appear in the policy, so more specific routes should appear before less specific routes. For example:

```yaml
policies:
  - from: http://from.example.com
    to: http://to.example.com
    prefix: /admin
    allowed_groups: ["superuser"]
  - from: http://from.example.com
    to: http://to.example.com
    allow_public_unauthenticated_access: true
```

In this example, an incoming request with a path prefix of `/admin` would be handled by the first route (which is restricted to superusers). All other requests for `from.example.com` would be handled by the second route (which is open to the public).

A list of policy configuration variables follows.


### Allowed Domains
- `yaml`/`json` setting: `allowed_domains`
- Type: list of `string`
- Required
- Example: `pomerium.io` , `gmail.com`

Allowed domains is a collection of whitelisted domains to authorize for a given route.


### Allowed Groups
- `yaml`/`json` setting: `allowed_groups`
- Type: list of `string`
- Required
- Example: `admins` , `support@company.com`

Allowed groups is a collection of whitelisted groups to authorize for a given route.


### Allowed IdP Claims
- `yaml`/`json` setting: `allowed_idp_claims`
- Type: map of `strings` lists
- Required

Allowed IdP Claims is a collection of whitelisted claim key-value pairs to authorize for a given route.

This is useful if your identity provider has extra information about a user that is not in the directory.  It can also be useful if you wish to use groups with the generic OIDC provider.

Example:

```yaml
  - from: http://from.example.com
    to: http://to.example.com
    allowed_idp_claims:
      family_name:
        - Doe
        - Smith
```

This policy would match users with the `family_name` claim containing `Smith` or `Doe`.

Claims are represented as a map of strings to a list of values:

```json
{
  "family_name": ["Doe"],
  "given_name": ["John"]
}
```

- Nested maps are flattened: `{ "a": { "b": ["c"] } }` becomes `{ "a.b": ["c"] }`
- Values are always a list: `{ "a": "b" }` becomes `{ "a": ["b"] }`


### Allowed Users
- `yaml`/`json` setting: `allowed_users`
- Type: list of `string`
- Required
- Example: `alice@pomerium.io` , `bob@contractor.co`

Allowed users is a collection of whitelisted users to authorize for a given route.


### CORS Preflight
- `yaml`/`json` setting: `cors_allow_preflight`
- Type: `bool`
- Optional
- Default: `false`

Allow unauthenticated HTTP OPTIONS requests as [per the CORS spec](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS#Preflighted_requests).


### Enable Google Cloud Serverless Authentication
- Environmental Variable: `ENABLE_GOOGLE_CLOUD_SERVERLESS_AUTHENTICATION`
- Config File Key: `enable_google_cloud_serverless_authentication`
- Type: `bool`
- Default: `false`

Enable sending a signed [Authorization Header](https://cloud.google.com/run/docs/authenticating/service-to-service) to upstream GCP services.

Requires setting [Google Cloud Serverless Authentication Service Account](./#google-cloud-serverless-authentication-service-account) or running Pomerium in an environment with a GCP service account present in default locations.


### From
- `yaml`/`json` setting: `from`
- Type: `URL` (must contain a scheme and hostname, must not contain a path)
- Schemes: `https`, `tcp+https`
- Required
- Example: `https://verify.corp.example.com`, `tcp+https://ssh.corp.example.com:22`

`From` is the externally accessible URL for the proxied request.

Specifying `tcp+https` for the scheme enables [TCP proxying](../docs/topics/tcp-support.md) support for the route. You may map more than one port through the same hostname by specifying a different `:port` in the URL.


### Kubernetes Service Account Token
- `yaml`/`json` setting: `kubernetes_service_account_token` / `kubernetes_service_account_token_file`
- Type: `string` or relative file location containing a Kubernetes bearer token
- Optional
- Example: `eyJ0eXAiOiJKV1QiLCJhbGciOiJ...` or `/var/run/secrets/kubernetes.io/serviceaccount/token`

Use this token to authenticate requests to a Kubernetes API server.

Pomerium will [impersonate](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#user-impersonation) the Pomerium user's identity, and Kubernetes RBAC can be applied to IdP user and groups.


### Signout Redirect URL
- Environmental Variable: `SIGNOUT_REDIRECT_URL`
- Config File Key: `signout_redirect_url`
- Type: `URL`
- Required
- Example: `https://signout-redirect-url.corp.example.com`

Signout redirect url is the url user will be redirected to after signing out.

You can overwrite this behavior by passing the query param `pomerium_redirect_uri` or post value `pomerium_redirect_uri`
to the `/.pomerium/signout/` endpoint.


### Path
- `yaml`/`json` setting: `path`
- Type: `string`
- Optional
- Example: `/admin/some/exact/path`

If set, the route will only match incoming requests with a path that is an exact match for the specified path.


### Prefix
- `yaml`/`json` setting: `prefix`
- Type: `string`
- Optional
- Example: `/admin`

If set, the route will only match incoming requests with a path that begins with the specified prefix.


### Prefix Rewrite
- `yaml`/`json` setting: `prefix_rewrite`
- Type: `string`
- Optional
- Example: `/subpath`

If set, indicates that during forwarding, the matched prefix (or path) should be swapped with this value.
For example, given this policy:

```yaml
from: https://from.example.com
to: https://to.example.com
prefix: /admin
prefix_rewrite: /
```

A request to `https://from.example.com/admin` would be forwarded to `https://to.example.com/`.


### Host Rewrite
- `yaml`/`json` settings: `host_rewrite`, `host_rewrite_header`, `host_path_regex_rewrite_pattern`, `host_path_regex_rewrite_substitution`
- Type: `string`
- Optional
- Example: `host_rewrite: "example.com"`

The `host` header can be preserved via the `preserve_host_header` setting or customized via 3 mutually exclusive options:

1. `preserve_host_header` when enabled, this option will pass the host header from the incoming request to the proxied host, instead of the destination hostname. It's an optional parameter of type `bool` that defaults to `false`.
    See [ProxyPreserveHost](http://httpd.apache.org/docs/2.0/mod/mod_proxy.html#proxypreservehost).
2. `host_rewrite` which will rewrite the host to a new literal value.
3. `host_rewrite_header` which will rewrite the host to match an incoming header value.
4. `host_path_regex_rewrite_pattern`, `host_path_regex_rewrite_substitution` which will rewrite the host according to a regex matching the path. For example with the following config:

    ```yaml
    host_path_regex_rewrite_pattern: "^/(.+)/.+$"
    host_path_regex_rewrite_substitution: \1
    ```

    Would rewrite the host header to `example.com` given the path `/example.com/some/path`.

The 2nd, 3rd and 4th options correspond to the envoy route action host related options, which can be found [here](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/route/v3/route_components.proto.html#config-route-v3-routeaction).


### Public Access
- `yaml`/`json` setting: `allow_public_unauthenticated_access`
- Type: `bool`
- Optional
- Default: `false`

**Use with caution:** Allow all requests for a given route, bypassing authentication and authorization. Suitable for publicly exposed web services.

If this setting is enabled, no whitelists (e.g. Allowed Users) should be provided in this route.


### Allow Any Authenticated User
- `yaml`/`json` setting: `allow_any_authenticated_user`
- Type: `bool`
- Optional
- Default: `false`

**Use with caution:** This setting will allow all requests for any user which is able to authenticate with our given identity provider. For instance, if you are using a corporate GSuite account, an unrelated gmail user will be able to access the underlying upstream.

Use of this setting means Pomerium **will not enforce centralized authorization policy** for this route. The upstream is responsible for handling any authorization.


### Regex
- `yaml`/`json` setting: `regex`
- Type: `string` (containing a regular expression)
- Optional
- Example: `^/(admin|superuser)/.*$`

If set, the route will only match incoming requests with a path that matches the specified regular expression. The supported syntax is the same as the Go [regexp package](https://golang.org/pkg/regexp/) which is based on [re2](https://github.com/google/re2/wiki/Syntax).


### Regex Rewrite
- `yaml`/`json` setting: `regex_rewrite_pattern`, `regex_rewrite_substitution`
- Type: `string`
- Optional
- Example: `{ "regex_rewrite_pattern":"^/service/([^/]+)(/.*)$", "regex_rewrite_substitution": "\\2/instance/\\1" }`

If set, the URL path will be rewritten according to the pattern and substitution, similar to `prefix_rewrite`.


### Outlier Detection
- `yaml`/`json` setting: `outlier_detection`
- Type: `object`
- Optional
- Example: `{ "consecutive_5xx": 12 }`

Outlier detection and ejection is the process of dynamically determining whether some number of hosts in an upstream cluster are performing unlike the others and removing them from the healthy load balancing set.

See Envoy [documentation](https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/upstream/outlier#arch-overview-outlier-detection) and [API](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/cluster/v3/outlier_detection.proto#envoy-v3-api-msg-config-cluster-v3-outlierdetection) for more details.


### Route Timeout
- `yaml`/`json` setting: `timeout`
- Type: [Go Duration](https://golang.org/pkg/time/#Duration.String) `string`
- Optional
- Default: `30s`

Policy timeout establishes the per-route timeout value. Cannot exceed global timeout values.


### Set Request Headers
- Config File Key: `set_request_headers`
- Type: map of `strings` key value pairs
- Optional

Set Request Headers allows you to set static values for given request headers. This can be useful if you want to pass along additional information to downstream applications as headers, or set authentication header to the request. For example:

```yaml
- from: https://verify.corp.example.com
  to: https://verify.pomerium.com
  allowed_users:
    - bdd@pomerium.io
  set_request_headers:
    # works auto-magically!
    # https://verify.corp.example.com/basic-auth/root/hunter42
    Authorization: Basic cm9vdDpodW50ZXI0Mg==
    X-Your-favorite-authenticating-Proxy: "Pomerium"
```


### Remove Request Headers
- Config File Key: `remove_request_headers`
- Type: array of `strings`
- Optional

Remove Request Headers allows you to remove given request headers. This can be useful if you want to prevent privacy information from being passed to downstream applications. For example:

```yaml
- from: https://verify.corp.example.com
  to: https://verify.pomerium.com
  allowed_users:
    - bdd@pomerium.io
  remove_request_headers:
    - X-Email
    - X-Username
```


### Rewrite Response Headers
- Config File Key: `rewrite_response_headers`
- Type: `object`
- Optional
- Example: `[{ "header": "Location", "prefix": "http://localhost:8000/two/", "value": "http://frontend/one/" }]`

Rewrite Response Headers allows you to modify response headers before they are returned to the client. The `header` field will match the HTTP header name, and `prefix` will be replaced with `value`. For example, if the downstream server returns a header:

```text
Location: http://localhost:8000/two/some/path/
```

And the policy has this config:

```yaml
rewrite_response_headers:
  - header: Location
    prefix: http://localhost:8000/two/
    value: http://frontend/one/
```

The browser would be redirected to: `http://frontend/one/some/path/`. This is similar to nginx's [`proxy_redirect` option](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_redirect), but can be used for any header.


### Redirect
- `yaml`/`json` setting: 'redirect'
- Type: object
- Optional
- Example: `{ "host_redirect": "example.com" }`

`Redirect` is used to redirect incoming requests to a new URL. The `redirect` field is an object with several possible
options:

- `https_redirect` (boolean): the incoming scheme will be swapped with "https".
- `scheme_redirect` (string): the incoming scheme will be swapped with the given value.
- `host_redirect` (string): the incoming host will be swapped with the given value.
- `port_redirect` (integer): the incoming port will be swapped with the given value.
- `path_redirect` (string): the incoming path portion of the URL will be swapped with the given value.
- `prefix_rewrite` (string): the incoming matched prefix will be swapped with the given value.
- `response_code` (integer): the response code to use for the redirect. Defaults to 301.
- `strip_query` (boolean): indicates that during redirection, the query portion of the URL will be removed. Defaults to false.

Either `redirect` or `to` must be set.


### To
- `yaml`/`json` setting: `to`
- Type: `URL` or list of `URL`s (must contain a scheme and hostname) with an optional weight
- Schemes: `http`, `https`, `tcp`
- Optional
- Example: `http://verify` , `https://192.1.20.12:8080`, `http://neverssl.com`, `https://verify.pomerium.com/anything/`, `["http://a", "http://b"]`, `["http://a,10", "http://b,20"]`

`To` is the destination(s) of a proxied request. It can be an internal resource, or an external resource. Multiple upstream resources can be targeted by using a list instead of a single URL:

```yaml
- from: https://example.com
  to:
  - https://a.example.com
  - https://b.example.com
```

A load balancing weight may be associated with a particular upstream by appending `,[weight]` to the URL.  The exact behavior depends on your [`lb_policy`](#load-balancing-policy) setting.  See [Load Balancing](/docs/topics/load-balancing) for example [configurations](/docs/topics/load-balancing.html#load-balancing-weight).

Must be `tcp` if `from` is `tcp+https`.

:::warning

Be careful with trailing slash.

With rule:

```yaml
- from: https://verify.corp.example.com
  to: https://verify.pomerium.com/anything
```

Requests to `https://verify.corp.example.com` will be forwarded to `https://verify.pomerium.com/anything`, while requests to `https://verify.corp.example.com/foo` will be forwarded to `https://verify.pomerium.com/anythingfoo`.To make the request forwarded to `https://httbin.org/anything/foo`, you can use double slashes in your request `https://httbin.corp.example.com//foo`.

While the rule:

```yaml
- from: https://verify.corp.example.com
  to: https://verify.pomerium.com/anything/
```

All requests to `https://verify.corp.example.com/*` will be forwarded to `https://verify.pomerium.com/anything/*`. That means accessing to `https://verify.corp.example.com` will be forwarded to `https://verify.pomerium.com/anything/`. That said, if your application does not handle trailing slash, the request will end up with 404 not found.

Either `redirect` or `to` must be set.

:::


### TLS Skip Verification
- Config File Key: `tls_skip_verify`
- Type: `bool`
- Default: `false`

TLS Skip Verification controls whether a client verifies the server's certificate chain and host name. If enabled, TLS accepts any certificate presented by the server and any host name in that certificate. In this mode, TLS is susceptible to man-in-the-middle attacks. This should be used only for testing.


### TLS Server Name
- Config File Key: `tls_server_name`
- Type: `string`
- Optional

TLS Server Name overrides the hostname specified in the `to` field. If set, this server name will be used to verify the certificate name. This is useful when the backend of your service is an TLS server with a valid certificate, but mismatched name.


### TLS Custom Certificate Authority
- Config File Key: `tls_custom_ca` or `tls_custom_ca_file`
- Type: [base64 encoded] `string` or relative file location
- Optional

TLS Custom Certificate Authority defines a set of root certificate authorities that clients use when verifying server certificates.

Note: This setting will replace (not append) the system's trust store for a given route.


### TLS Downstream Client Certificate Authority
- Config File Key: `tls_downstream_client_ca` or `tls_downstream_client_ca_file`
- Type: [base64 encoded] `string` or relative file location
- Optional

If specified downstream clients (eg a user's browser) will be required to provide a valid client TLS
certificate. This overrides the global `client_ca` option for this route.


### TLS Client Certificate
- Config File Key: `tls_client_cert` and `tls_client_key` or `tls_client_cert_file` and `tls_client_key_file`
- Type: [base64 encoded] `string` or relative file location
- Optional

Pomerium supports client certificates which can be used to enforce [mutually authenticated and encrypted TLS connections](https://en.wikipedia.org/wiki/Mutual_authentication) (mTLS). For more details, see our [mTLS example repository](https://github.com/pomerium/pomerium/tree/master/examples/mutual-tls) and the [certificate docs](../docs/topics/certificates.md).


### Pass Identity Headers
- `yaml`/`json` setting: `pass_identity_headers`
- Type: `bool`
- Optional
- Default: `false`

When enabled, this option will pass identity headers to upstream applications. These headers include:

- X-Pomerium-Jwt-Assertion
- X-Pomerium-Claim-*


### SPDY
- Config File Key: `allow_spdy`
- Type: `bool`
- Default: `false`

If set, enables proxying of SPDY protocol upgrades.


### Cluster Name
- Config File Key: `name`
- Type: `string`
- Optional

Runtime metrics for this policy would be available under `envoy_cluster_`*`name`* prefix.


### Load Balancing Policy
- Config File Key: `lb_policy`
- Type: `enum`
- Optional

In presence of multiple upstreams, defines load balancing strategy between them.

See [Envoy documentation](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/cluster/v3/cluster.proto#envoy-v3-api-enum-config-cluster-v3-cluster-lbpolicy) for more details.

- [`ROUND_ROBIN`](https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/upstream/load_balancing/load_balancers#weighted-round-robin) (default)
- [`LEAST_REQUEST`](https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/upstream/load_balancing/load_balancers#weighted-least-request) and may be further configured using [`least_request_lb_config`](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/cluster/v3/cluster.proto#envoy-v3-api-msg-config-cluster-v3-cluster-leastrequestlbconfig)
- [`RING_HASH`](https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/upstream/load_balancing/load_balancers#ring-hash) and may be further configured using [`ring_hash_lb_config`](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/cluster/v3/cluster.proto#config-cluster-v3-cluster-ringhashlbconfig) option
- [`RANDOM`](https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/upstream/load_balancing/load_balancers#random)
- [`MAGLEV`](https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/upstream/load_balancing/load_balancers#maglev) and may be further configured using [`maglev_lb_config`](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/cluster/v3/cluster.proto#envoy-v3-api-msg-config-cluster-v3-cluster-maglevlbconfig) option

Some policy types support additional [configuration](#load-balancing-policy-config).


### Load Balancing Policy Config
- Config File Key: `least_request_lb_config`, `ring_hash_lb_config`, `maglev_lb_config`
- Type: `object`
- Optional

When [`lb_policy`](#load-balancing-policy) is configured, you may further customize policy settings for `LEAST_REQUEST`, `RING_HASH`, AND `MAGLEV` using one of the following options.

- [`least_request_lb_config`](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/cluster/v3/cluster.proto#envoy-v3-api-msg-config-cluster-v3-cluster-leastrequestlbconfig)
- [`ring_hash_lb_config`](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/cluster/v3/cluster.proto#config-cluster-v3-cluster-ringhashlbconfig)
- [`maglev_lb_config`](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/cluster/v3/cluster.proto#envoy-v3-api-msg-config-cluster-v3-cluster-maglevlbconfig)

See [Load Balancing](/docs/topics/load-balancing) for example [configurations](/docs/topics/load-balancing.html#load-balancing-method)


### Health Checks
- Config File Key: `health_checks`
- Type: `array of objects`
- Optional

When defined, will issue periodic health check requests to upstream servers. When health checks are defined, unhealthy upstream servers would not serve traffic.
See also `outlier_detection` for automatic upstream server health detection.
In presence of multiple upstream servers, it is recommended to set up either `health_checks` or `outlier_detection` or both.

See [Envoy documentation](https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/upstream/health_checking) for a list of [supported parameters](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/core/v3/health_check.proto#envoy-v3-api-msg-config-core-v3-healthcheck).

Only one of `http_health_check`, `tcp_health_check`, or `grpc_health_check` may be configured per health_check object definition.

- [TCP](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/core/v3/health_check.proto#envoy-v3-api-msg-config-core-v3-healthcheck-tcphealthcheck)
- [HTTP](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/core/v3/health_check.proto#envoy-v3-api-msg-config-core-v3-healthcheck-httphealthcheck)
- [GRPC](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/core/v3/health_check.proto#envoy-v3-api-msg-config-core-v3-healthcheck-grpchealthcheck)

See [Load Balancing](/docs/topics/load-balancing) for example [configurations](/docs/topics/load-balancing.html#active-health-checks).


### Websocket Connections
- Config File Key: `allow_websockets`
- Type: `bool`
- Default: `false`

If set, enables proxying of websocket connections.

:::warning

**Use with caution:** websockets are long-lived connections, so [global timeouts](#global-timeouts) are not enforced (though the policy-specific `timeout` is enforced). Allowing websocket connections to the proxy could result in abuse via [DOS attacks](https://www.cloudflare.com/learning/ddos/ddos-attack-tools/slowloris/).

:::


## Authorize Service

### Authorize Service URL
- Environmental Variable: `AUTHORIZE_SERVICE_URL` or `AUTHORIZE_SERVICE_URLS`
- Config File Key: `authorize_service_url` or `authorize_service_urls`
- Type: `URL`
- Required
- Example: `https://authorize.corp.example.com`

Authorize Service URL is the location of the internally accessible authorize service. Multiple URLs can be specified with `authorize_service_url`.


### Google Cloud Serverless Authentication Service Account
- Environmental Variable: `GOOGLE_CLOUD_SERVERLESS_AUTHENTICATION_SERVICE_ACCOUNT`
- Config File Key: `google_cloud_serverless_authentication_service_account`
- Type: [base64 encoded] `string`
- Optional

Manually specify the service account credentials to support GCP's [Authorization Header](https://cloud.google.com/run/docs/authenticating/service-to-service) format.

If unspecified:

- If [Identity Provider Name](#identity-provider-name) is set to `google`, will default to [Identity Provider Service Account](#identity-provider-service-account)
- Otherwise, will default to ambient credentials in the default locations searched by the Google SDK. This includes GCE metadata server tokens.


### Signing Key
- Environmental Variable: `SIGNING_KEY`
- Config File Key: `signing_key`
- Type: [base64 encoded] `string`
- Optional

Signing Key is the private key used to sign a user's attestation JWT which can be consumed by upstream applications to pass along identifying user information like username, id, and groups.

If set, the signing key's public key will can retrieved by hitting Pomerium's `/.well-known/pomerium/jwks.json` endpoint which lives on the authenticate service. (If running the authentication service separately, this option must also be set there.)

For example:

```bash
$ curl https://authenticate.int.example.com/.well-known/pomerium/jwks.json | jq
```

```json
{
  "keys": [
    {
      "use": "sig",
      "kty": "EC",
      "kid": "ccc5bc9d835ff3c8f7075ed4a7510159cf440fd7bf7b517b5caeb1fa419ee6a1",
      "crv": "P-256",
      "alg": "ES256",
      "x": "QCN7adG2AmIK3UdHJvVJkldsUc6XeBRz83Z4rXX8Va4",
      "y": "PI95b-ary66nrvA55TpaiWADq8b3O1CYIbvjqIHpXCY"
    }
  ]
}
```

If no certificate is specified, one will be generated and the base64'd public key will be added to the logs. Note, however, that this key be unique to each service, ephemeral, and will not be accessible via the authenticate service's `jwks_uri` endpoint.


### Signing Key Algorithm
- Environmental Variable: `SIGNING_KEY_ALGORITHM`
- Config File Key: `signing_key_algorithm`
- Type: `string`
- Options: `ES256` or `EdDSA` or `RS256`
- Default: `ES256`

This setting specifies which signing algorithm to use when signing the upstream attestation JWT. Cryptographic algorithm choice is subtle, and beyond the scope of this document, but we suggest sticking to the default `ES256` unless you have a good reason to use something else.

Be aware that any RSA based signature method may be an order of magnitude lower than [elliptic curve] variants like EdDSA (`ed25519`) and ECDSA (`ES256`). For more information, checkout [this article](https://www.scottbrady91.com/JOSE/JWTs-Which-Signing-Algorithm-Should-I-Use).


[base64 encoded]: https://en.wikipedia.org/wiki/Base64
[elliptic curve]: https://wiki.openssl.org/index.php/Command_Line_Elliptic_Curve_Operations#Generating_EC_Keys_and_Parameters
[environmental variables]: https://en.wikipedia.org/wiki/Environment_variable
[identity provider]: ../docs/identity-providers/
[json]: https://en.wikipedia.org/wiki/JSON
[letsencrypt]: https://letsencrypt.org/
[oidc rfc]: https://openid.net/specs/openid-connect-core-1_0.html#AuthRequest
[okta]: ../docs/identity-providers/okta.md
[script]: https://github.com/pomerium/pomerium/blob/master/scripts/generate_wildcard_cert.sh
[signed headers]: ../docs/topics/getting-users-identity.md
[toml]: https://en.wikipedia.org/wiki/TOML
[yaml]: https://en.wikipedia.org/wiki/YAML